Nerve Lesions and Disordes of Gait

Question 1

eccentric contraction

Answer 1

• Lengthening contraction -may be used as a “braking contraction” to slow down a movement ex: lying on back and lowering straight legs (hip flexors)

Question 2

Isometric contraction

Answer 2

• Contraction at fixed length - can occur in 2-joint muscles during weight bearing ex: isometric contraction of rectus femoris limits knee flexion and aids in hip flexion at the end of stance

Question 3

Reverse action

Answer 3

Occurs when the insertion is fixed and the origin is mobile

Question 4

muscle actions

Answer 4

shortening contractions (concentric contractions) that move insertion toward origin

Question 5

Gait can be broken into 2 categories, name them

Answer 5

stance (support) swing

Question 6

Gluteus medius and gluteus minimus role in gait

Answer 6

controls drop of contralateral side of pelvis (reverse action) at heel strike, loading response O: ilium moves toward I: greater trochanter *superior gluteal n.

Question 7

Positive Trendelenburg sign

Answer 7

Injury to superior gluteal nerve -pelvis drops on unsupported side

Question 8

Uncompensated trendelenburg gait

Answer 8

hip drops on unsupported side during stance

Question 9

Compensated trendelenburg gait

Answer 9

lean away from unsupported side to raise pelvis and allow limb to clear the ground during stance

Question 10

Where is a safe place to inject in the gluteal muscles to avoid injury to superior gluteal n.?

Answer 10

Question 11

What is Gluteus maximus role during gait

Answer 11

isometric contraction to prevent jackknifing of trunk from forward momentum at heel strike

*pulls trunk back (O: ilium, saccrum, coccyx -> I: gluteal tuberosity, IT tract)

Question 12

What is hamstrings action during gait

Answer 12

eccentric contraction to decelerate leg at end of swing phase (terminate swing phase)

• also biceps femoris prevents jackknifing of trunk from forward momentum at heel strike

Question 13

What is iliopsoas role in gait?

Answer 13

*at fast speeds only

• eccentric contraction to decelerate hip extension at end of stance
• concentric contraction to flex hip for start of swing phase

Question 14

What is the role of the quadriceps femoris muscles during gait

Answer 14

eccentric contraction to limit knee flexion (prevent knee collapse) during early stance

* forward momentum would keep body going forward

• recuts femoris: isometric contraction limits knee flexion and aids hip flexion at the end of stance

Question 15

Femoral nerve mononeuropathy would cause what affect in gait

Answer 15

-knee may buckle after heel strike

*quadriceps muscles affected

Question 16

Compensation gait with femoral nerve damage

Answer 16

• lean forward in early stance to place center of gravity anterior to knee joint, to force knee into full extension
• may put hand on distsal femur to preent accidently flexion of knee in early stance
• cannot run and stairs difficulty

Question 17

What are the hip adductors (adductor magnus, adductor longus primarily) role in gait

Answer 17

counteract lateral displacement of limb during swing

Question 18

What is the anterior leg muscles (primarily tibialis anterior, extensor digitorum longus) role in gait

Answer 18

• concentric contraction to dorsiflex ankle/extend toes (to avoid foot drag) during swing
• eccentric contraction to lower foot/toes to ground at heel strike (preent foot slap)

*tibialis anterior helps maintain arches of foot

Question 19

What is the role of the lateral leg muscles (fibularis longus and brevis) during gait

Answer 19

Role: evert and weakly plantarflex ankle

• resists tendency of foot to invert when weight is transferred to ball of foot
• assists posterior leg in resisting ankle collapse in second 1/2 of stance

*fibularis longus helps maintain arches of foot

Question 20

What is the role of ankle plantarflexors (soleus, gastrocnemius) in gait

Answer 20

• eccentric contraction to prevent ankle collapse in second 1/2 of stance
• concentrc contraction just before toe off (propulsive force at heel off)

Question 21

What is the role of intrinsic muscles of the plantar foot (flexor digitorum brevis, quadratus plantae, abductor hallucis, abductor digiti minimi)

Answer 21

support longitudinal arch at end of support

• flexors of toes: concentric contraction at toe off (propulsive force)

Question 22

Why is the common fibular nerve the most commonly injured in the lower extremity? Where would a patient loose sensation?

Answer 22

• superficial position near fibular neck (surgery or trauma)
• lateral leg

Question 23

Common fibular nerve mononeuropathy would have what effect on gait

Answer 23

• paralysis of anterior leg muscles (no ankle dorsiflexion)
• FOOT DROP-toes do not clear ground during swing
• FOOT SLAP at heel strike

Question 24

Describe steppage gait and circumduction gait and vaulting. What defect is this gait trying to compensate for?

Answer 24

• Steppage gait: lift foot high to clear groun
• Circumduction gait: swing out gait
• vaulting: get up on toes to clear the affected limb during swing
• common fibular nerve mononeuropathy

Question 25

How would tibial nerve mononeuropathy (very rare) affect gait?

Answer 25

* paralysis of posterior leg (soleus, gastrocnemius) and plantar foot muscles * no propulsive force in push off * cannot prevent ankle dorsiflexion (collapse) during midstance